Pipe working carriage

ABSTRACT

A pipe working carriage which is adapted to travel along a track encircling the exterior of a pipe. The carriage includes a body, wheels for engaging the track, and a drive system which engages a cylindrical surface parallel to the axis of the pipe. This abstract is neither intended to define the invention of the application, which of course is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

United States Patent 1191 Homes 1451 Aug. 21, 1973 PIPE WORKING CARRIAGE[75] inventor: Samuel J. Homes, Houston, Tex.

[73] Assignee: Crc-Croee lnternatlonahlnm,

3,084,246 4/1963 Ruppel et al 219/125 R 2,941,067 6/1960 Kitrell 219/125R 2,596,322 5/1952 Zumwalt.... 228/32 X 2,466,143 4/1949 Houston, Tex.Primary Examiner-J. Spencer Overholser [22] filed: 1971 AssistantEJtaminer-Robert J. Craig [2]] A N1 3,169 A ttorney-J. VincentMartin,Jack R. Springgate et a1.

[52] US. Cl 228/29, 29/484, 219/59, [57] 'f 'f 228/32 A pipe workmgcarnage whlch 1s adapted to travel [51] Int. Cl 823k 5/00 along a trackencircling the ammo" a Pipe' The [58] Field of Search 228/25, 29, 32,45; riage includes a body, Wheels for "m i the track 266/23; 219/59, 68;198/184, 193; 29/484 and a drive system which engages a cylindricalsurface parallel tothe axis of the pipe. This abstract is neither [56]References CM intended to define the invention of the application, whichof course is measured by the claims, nor is it in- UNTED STATESPATENTStended to be limiting as to the scope of the invention 3,441,191 4/1969Cerneau 228/32 in any way 3,268,707 8/1966 Thomas..... 219/125 R3,266,701 8/1966 Peignen 228/29 12 Claims,- 8 Drawing Figures i1 25 I I27 26 '1 1 w. [9 i A i Young 228/32 X PATENTEDAUGZ] 397s SHEET 1 [1F 3SAMUEL J Ham/5s INVENTOR.

BY Q A TORNEYS PATENTEDMIGZI I975 SHEET 3 [IF 3 SAMUEL J H0M5 INVENTOR.Y MMWMMQ ATTGENEYS SUMMARY OF THE INVENTION This invention relates to apipe working carriage which is adapted to travel along a trackcircumferentially disposed about the exterior of a pipe while holding atool, such as a cutting torch or welding apparatus, for performing workon the pipe such as beveling or welding. It relates particularly to sucha carriage which is driven by direct engagement with a cylindricalsurface parallel to the axis of the pipe, such as the exterior surfaceof the pipe or the top surface of the track.

Pipelines for the carrying of gas, oil or like fluids from one area toanother are frequently constructed in large diameters such as from 12inches to 36 inches, or larger, depending on he desired capacity. Inconstructing such pipelines, the usual practice is to lay the largediameter pipe sections end to end, and then weld the abutting endstogether. In preparation for such welding, the abutting ends of eachpipe are first prepared, as by beveling, so thata sound welded joint maybe made. After the beveling operation, the ends are then joined bywelding circumferentially around the pipe. The carrying out of suchbeveling and welding operations by hand is tedious and expensive, andfrequently results in a poorer weld than could be achived usingautomatic beveling and welding machines. It has, therefore, beendesirable to provide a portable beveling and welding machine which maybe used in the field. Such a portable beveling machine is disclosed inU.S. Pat. No. 2,705,629 issued Apr. 5, 1955 to F. S. Miller. The machinethere disclosed uses a flexible annular track band which is mountedcircumferentially about the exterior of the pipe, and a powered carriagewhich engages the edges of the track and holds a cutting torch forcutting a bevel as the machine is moved about the track. As shown inFIGS. 4 andS of the Miller Patent, the carriage is mounted on the trackby means of grooved wheels which engage the external edges of theDESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENT These and otherobjects and advantages of the invention will become apparent from thedrawings, the specification and claims.

In the accompanying drawings, which illustrate the preferred embodimentof the invention, and wherein like numerals indicate like parts:

FIG. 1 is a top plan view of the preferred form of carriage, in,accordance with the present invention, mounted on a section of track;

FIG. 2 is a view in side elevation, partly in phantom, of the carriageof FIG. I;

FIG. 3 is a view in end elevation and in section taken along the line3-3 of FIG. 1, showing in detail the means for mounting the carriage onthe track;

FIG. 4 is a sectional view in elevation taken along line 4-4 of FIG. 1,showing the cam means for removing the carriage from the track;

FIG. 5 is a view in perspective, partly in section, of the drive systemof the carriage of FIG. 1;

FIG. 6 is a sideelevational view, partly in section, taken along line 66of FIG. 1, and illustrating the drive system engaging the exteriorsurface of the pipe;

FIG. 7 is a view in sectional elevation, taken along line 77 of FIG. 6,illustrating details of the drive system; and

FIG. 8 is an enlarged sectional detail taken along line 88 of FIG. 6,showing the idler roller mounting.

In FIGS. 1 and 2 is shown the carriage I0 mounted on a track 11. Thetrack is preferably one such as that disclosed in the aforementionedMiller patent, and

track. These same wheels are used for locomotion;

power means are provided for rotating the wheels on each side of thetrack in opposite directions so that the carriage will move along thetrack. A difficulty which has been encountered in the use of this deviceis a tendency on the part of the track band to buckle during use. Thisis due to the relatively thin, flexible track which is used and to thefact that the wheels on each side of the track tightly engage the trackto provide the friction for driving the carriage. The result is a tightengagement which tends to buckle the track. It is, accordingly, aprimary object of this invention to provide a pipe beveling and weldingcarriage which may be used with an annular track band and whichovercomes the deformation problem of the prior art carriage;

Another object is to provide such a carriage wherein the drive mechanismoperates by direct engagement with a circumferential surface parallel tothe axis of the pipe rather than the edges of the track.

Another object is to provide such a carriage which improves over theprior art carriage by driving off the external surface of the pipe.

A more specific object is to provide such a carriage including resilientmeans in the drive system for accommodating irregularities in theexternal surface of the pipe, and for exerting constant pressure on thefriction means which engage the pipe.

comprises a flexible metal band 12 having a plurality of spaced radiallydisposed and inwardly extending locating pins 13 which locate the band12 a preselected distance above the surface of the pipe P. A coupling(not shown) is provided on each end of the band so that the two ends canbe joined to position the track about the exterior of apipe as shown inthe Miller Patent.

The carriage 10 includes a body comprised of two frames 14 and 15pivotally connected by two pivot pins 16. This pivotal connectionpermits the carriage wheels to be engaged or disengaged from the track11, as will be explained hereinafter. Each frame has an outer downwardlyextending projection forming skirtsl4s and 15s. Such skirts may providemeans for attaching a work tool to the carriage as shown in FIG. 3.There is shown in phantom line a welding tool 17 attached to skirt 15sby means of bolt 18.

Means for mounting the carriage on the track for movement therealong areprovided on the carriage 10 for engagement with the track 11. In thepreferred carriage these comprise two pair of idler wheels 19, one wheel19 being disposed. at each of the four corners of the carriage. As shownmost clearly in FIG. 3, each wheel 19 has rigidly attached at its lowerend a circular disc or bushing 20 having a circumferential groove 21therein. Grooves 21 are specifically provided to engage the opposedlateral edges of the track band 12 and roll along the lateral edges ofthe track as the carriage progresses around the pipe. The upwardly anddownwardly facing annular shoulders 21a and 21b (FIG. 4) of the grooves21 act to retain the carriage against radial displacement relative tothe track 11. At the upper end of each wheel 19 is a ball bearingincluding ball race 23' on the wheel and race 24 on a tubular wheelhousing 26 carried by the carriage with balls 25 disposed between theraces. The ball bearing arrangement permits rotation of the wheels 19and discs 20 relative to the carriage body, and carries vertical andhorizontal loads. A cap 26a fits within the top of tubular wheel housing26 to protect the bearings from contamination.

Each tubular wheel housing 26 has positioned around its lower end ballportion 27 which mates with socket 28 in the body frame sections 14 and15. Formed on the upper end of each wheel housing 26 is an upstandingflange 29 having an arcuate slot 30 therein (FIG. 2). A bolt 31 fitsthrough each slot 30 and a corresponding hole (not shown) in the bodyframe section and is held at its threaded end by nut 32 (FIG. 3).

This arrangement provides means whereby the wheels 19 may be adjustedarcuately in a plane perpendicular to the axis of pipe P so that thesame carriage maybe used on different diameter pipes. To adjust thewheels, nuts 32 are loosened so that flange 29 may move relative to thebody frame. The wheels may then be pivoted by provision of balls andsockets 27 and 28 through an arc in the same plane as slots 30. Thelower end of the wheels (mounting bushings 20) are pivoted toward eachother to accommodate a smaller diameter pipe and away from each other toaccommodate pipes of larger diameter. Once the adjustment is made, nuts32 are re'tightened to lock the wheels in their new position.

Positive engagement of idler wheels 19 with the track band 12 isprovided by two compression coil springs 33 (FIGS. 1 and 4); Each coilspring 33 has its lower end in circular recess 34 in a lateral rib ofbody frame 15, and its upper end bears against the under side of frame14. Springs 33 tend to pivot the lower ends of the two body framestoward each other about pivot pin 16 in a direction urging the bushings20 toward each other, and thereby serve to keep the grooves 21 ofbushings 20 on wheels 19 engaged with the edges 22 of track band 12.

Means are also provided for overcoming the force of springs 33 when itis desired to release or re-engage the carriage 10. As best shown inFIGS. 1 and 4, each of v the'two laterally extending ribs of frame 14has formed on its upper face tapering cam surface 35. Two ellipticalcams 36 carried by frame engage cam surfaces 35 and are joined by ashaft 37 having a handle 38. By depressing handle 38 hacounter-clockwise direction (as viewed in FIG. 4) elliptical earns 36will engage and depress cam surfaces 35, causing frame 14 to pivot aboutpivot pins 16 in a clockwise direction relative to frame 15. This servesto disengage the two wheels 19 carried by frame 14 from the track band12 so that the carriage may be removed from the track. The process isreversed to mount the carriage on the track; that is, the cam is firstdepressed, the carriage positioned on the track and the cam released toengage grooves 21 of bushings with the track band.

In the prior art carriages of this type, as for example in the MillerPatent referred to above, the same grooved wheels which retain thecarriage on the track are powered to drive the carriage therealong.Since both the track and wheels are made of steel, or some similarsubstance having a low coefficient of friction, it is necessary for thewheels to grip the track very tightly in order to generate sufficientfriction to drive the carriage. This frequently has resulted in thetrack band being buckled or deformed due to the compressive force of thedrive wheels. This problem is overcome in the carriage of the presentinvention by providing drive means on the carriage body for moving thecarriage along the track, which drive means include friction means fordirect engagement with a cylindrical surface parallel to the axis of thepipe.

The preferred form of this drive system is shown in FIGS. 1 and 5through 8. It-includes a drive body 39 in the form of a vertical platewith a dovetail slot 40 formed on the side adjacent the carriage 10 bytwo vertical ribs 39a and 39b. Slot 40 engages a corresponding dovetailslide 41 on frame 14 to retain the drive body against movement relativeto the carriage in other than a vertical direction. A spacer busing41a(FIG. 1) fits between slide 41 and rib 39b of drive body 39. Coiledtension springs 42 (FIG. 2) with their lower ends attached to body frame14 and their upper ends to drive body 39 provide resilient means urgingthe drive body downwardly relative to the carriage. Attached to theupper end of drive body 39 by a pivot pin 43 is an elliptical cam 44(FIG. 7) having an actuating handle 45 (FIG. 6). Cam 44 engages theupper edge 41a of slide 41 so that rotation of the elliptical cam 44 byhandle 45 until its enlarged side is downward will move the drive body39 upwardly relative to slide 41 and the carriage body.

Extending outwardly from the mid portion of drive body 39 on the sideopposite ribs 394 and 39b is a drive sprocket 46 .having multiplesplines 46a. Disposed below and on either side of drive sprocket 46 aretwo pair of idler rollers including .upper rollers 47 and lower rollers48. Upper rollers 47 are smooth surfaced, while lower rollers 48 havesplines 48a. As shown most clearly in FIGS. 6 and 8, the idler rollersare rotatably mounted in pairs on left-hand and right-hand rollerbrackets 49. Each roller bracket 49 has two pins 50 extending outwardlytherefrom on which the idler rollers are mounted by means of ballbearings including ball races 51 and balls 52. The roller brackets 49are themselves pivotally mounted on the drive body 39 by pivot pins 53.Each roller bracket 49 has an inwardly extending horizontal projection49a. On the front end of each projection 49a is an upstanding taperedlug 49b around which is disposed a compression coil spring. 54.'Theupper ends of the two springs 54 engage the lower side of springretainer 55 mounted on the drive body 39 with screws 56. Coil springs 54urge projections 49a of the roller brackets 49 downwardly, tending topivot the left-hand roller bracket about its pivot pin 53 in a clockwisedirection, andto pivot the right-hand roller bracket in acounter-clockwise direction, said springs 54 and roller brackets 49comprise resilient tensioning means the purpose of which is to keep thepreferred friction driving means tensioned as explained hereinafter.

Friction means for driving the carriage are provided by a flexibleendless drive belt 57 having splines 57a on its inner surface. As shownin FIG. 6, the belt extends around the drive sprocket 46 and idlerrollers 48 and under the idler rollers 47. The splines 57a of the drivebelt mesh with the splines of the drive sprocket and rollers 48 so thatthe belt 57 progresses at a predetermined ratio of the speed of drivesprocket 46. The pivoting action of the idler rollers under the urgingof springs 54 serves to keep the drive belt taut while permittingsufficient flexibility for the belt to accommodate irregularitiesencountered on the pipes surface.

Similarly, the drive body 39 and belt 57 are urged downwardly intodriving engagement with the pipe by the action of tension springs 42which urge the drive body downwardly relative to the carriage l0. Cam 44on the drive body may be used to lift the drive body and with it thedrive belt 57, into a raised position where it does not engage the pipeP.

The outer surface of the pipe P and the upper and lower surfaces of thetrack band 12 provide cylindrical surfaces parallel to the axis of thepipe P off which the carriage may be driven without tending to bucklethe track as in the prior art carriage; and frictional drive meansdriving off any of said surfaces are included within the scope of thepresent invention and the appended claims.

Power means for driving sprocket 46 to move the friction means 57 arepreferably provided by an electric motor 58 carried by the drive body 39(FIG. 3), which motor drives the sprocket 46 through a gear box 59. Ahand-powered crank, or other suitable power means, could be used in lieuof the electric motor 58.

in operation, the carriage is mounted on the track as previouslydescribed, and the motor startedto drive the belt 57. As thecarriagemoves around the track, a tool carried by the carriage, suchas a cuttingtorch or welding apparatus, will be able to perform work on the pipesuch as cutting, beveling or welding.

It is therefore seen that a pipe working carriage is provided inaccordance with the objects of the present invention, which carriage hasan improved drive mechanism which drives off a cylindrical surfaceparallel to the axis of the pipe rather than off the edges of the trackband 12 as in the prior art carriage.

The foregoing disclosure and description of the inventionareillustrative and explanatory thereof, and various changes in thesize, shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:

l. A pipe working carriage for use with a track encircling the exteriorof a pipe comprising:

a body;

means on the body for mounting the carriage on said track for movementtherealong,

said mounting means comprising grooved idler wheels for engagement withthe edges of said track, and;

means on the body for driving the carriage along the track includingmeans for frictionally engaging a cylindrical surface parallel to theaxis of the pipe, and

means for moving said engaging means relative to said surface. 7

2. The carriage according to claim 1 including resilient means on saidbody for retaining said grooves in engagement with said track.

3. The carriage according to claim 1 wherein means are provided foradjusting the idler wheels arcuately in a plane perpendicular to theaxis of said pipe whereby said carriage may be used in connection withdifferent diameter pipes.

4. A pipe working carriage for use with a track encircling the exteriorof a pipe comprising a carriage body; means for engaging said body withsaid track for 5 movement around the track;

means for attaching to the body a tool for doing work on the pipe; drivemeans on the body for moving the carriage along the track including, adrive body carried by said carriage body, rollers on said drive body, anendless belt disposed about said rollers and adapted to engage theexternal surface of said pipe, and means for driving one of said rollersto drive said belt. 5. The carriage according to claim 4 whereinresilient tensioning means are provided on said drive body formaintaining tension in said endless belt.

6. The carriage of claim 4 wherein resilient means are provided on saidcarriage body for urging said drive body downwardly relative to saidcarriage body.

7. A pipe working carriage for use with a track encircling the exteriorof a pipe comprising a carriage body formed of two frames pivotallyconnected; I idler wheels on said body adapted to engage said track tosupport said carriage body for movement around said pipe; means forattaching to the body a tool for doing work on the pipe; I drive meanson the body for moving the carriage along the track including, 7 a drivebody mounted on said carriage body, a drive sprocket on said drive body,idler rollers on said drive body, an endless drive belt disposed aboutsaid drive sprocket and idler rollers and adapted to engage the exteriorof said pipe, and

power means for driving said drive sprocket to drive said drive belt. 8.The carriage according to claim 7 wherein each of said idler wheelsincludes acircular groove for engage.-

ment with the lateral edges of said track. body includes resilient meansfor urging said circular grooves into engagementwith said track.

10. The carriage according to claim 9 wherein said body includes meansfor overcoming the effect of said resilient means to facilitate engagingand disengaging said circular grooveson said idler wheels with saidtrack.

11. The carriage according to claim 7 wherein said idler wheels arearcuately adjustable to accommodate pipes of different diameter.

12. The carriage according to claim 7 wherein said drive body isslidably mounted on said carriage body for movement in a verticaldirection and includes means for resiliently urging said drive bodydownwardly relative to said carriage body to hold said endless belt indriving engagement with the pipe.

9. Thecarriage according to claim 8 wherein said

1. A pipe working carriage for use with a track encircling the exteriorof a pipe comprising: a body; means on the body for mounting thecarriage on said track for movement therealong, said mounting meanscomprising grooved idler wheels for engagement with the edges of saidtrack, and; means on the body for driving the carriage along the trackincluding means for frictionally engaging a cylindrical surface parallelto the axis of the pipe, and means for moving said engaging meansrelative to said surface.
 2. The carriage according to claim 1 includingresilient means on said body for retaining said grooves in engagementwith said track.
 3. The carriage according to claim 1 wherein means areprovided for adjusting the idler wheels arcuately in a planeperpendicular to the axis of said pipe whereby said carriage may be usedin connection with different diameter pipes.
 4. A pipe working carriagefor use with a track encircling the exterior of a pipe comprising acarriage body; means for engaging said body with said track for movementaround the track; means for attaching to the body a tool for doing workon the pipe; drive means on the body for moving the carriage along thetrack including, a drive body carried by said carriage body, rollers onsaid drive body, an endless belt disposed about said rollers and adaptedto engage the external surface of said pipe, and means for driving oneof said rollers to drive said belt.
 5. The carriage according to claim 4wherein resilient tensioning means are provided on said drive body formaintaining tension in said endless belt.
 6. The carriage of claim 4wherein resilient means are provided on said carriage body for urgingsaid drive body downwardly relative to said carriage body.
 7. A pipeworking carriage for use with a track encircling the exterior of a pipecomprising a carriage body formed of two frames pivotally connected;idler wheels on said body adapted to engage said track to support saidcarriage body for movement around said pipe; means for attaching to thebody a tool for doing work on the pipe; drive means on the body formoving the carriage along the track including, a drive body mounted onsaid carriage body, a drive sprocket on said drive body, idler rollerson said drive body, an endless drive belt disposed about said drivesprocket and idler rollers and adapted to engage the exterior of saidpipe, and power means for driving said drive sprocket to drive saiddrive belt.
 8. The carriage according to claim 7 wherein each of saididler wheels includes a circular groove for engagement with the lateraledges of said track.
 9. The carriage according to claim 8 wherein saidbody includes resilient means for Urging said circular grooves intoengagement with said track.
 10. The carriage according to claim 9wherein said body includes means for overcoming the effect of saidresilient means to facilitate engaging and disengaging said circulargrooves on said idler wheels with said track.
 11. The carriage accordingto claim 7 wherein said idler wheels are arcuately adjustable toaccommodate pipes of different diameter.
 12. The carriage according toclaim 7 wherein said drive body is slidably mounted on said carriagebody for movement in a vertical direction and includes means forresiliently urging said drive body downwardly relative to said carriagebody to hold said endless belt in driving engagement with the pipe.